Conventional tile roofing materials, including those made from cement or clay, weigh approximately 1,000 pounds per square (100 square feet) and thus require buildings to have considerably greater structural strength to accommodate their weight. Examples of such conventional roofing materials are shown in U.S. Pat. Nos. 4,251,527; 4,010,232; 4,191,722; 3,025,772; 3,330,080; 3,897,667; 3,760,546; and 4,178,727.
Normally, there is a direct correlation between the structural strength requirement of a building and the cost of the building, such that the greater the structural strength, the greater the cost.
The present invention provides a roof tile having a weight of approximately 430 pounds per square, less than one-half of conventional roofing materials, so that structural requirements of a building can be kept to a minimum, thereby eliminating substantial cost required for conventional heavy roof material.
Due to numerous fires in recent years, many municipalities have passed stringent fire safety laws requiring fire retardant roofing materials for new construction as well as for repairs and replacement of roofs of buildings. Under these laws, a great number of existing structures, particularly those having wood shake roofs, would require reinforcement of their roof trusses, as well as walls and foundations to accommodate a conventional cement or clay tile roof. The use of the present invention would eliminate such reinforcement otherwise required, and the attendant cost.
Further, conventional cement and clay tiles are subject to water absorption which renders them susceptible to cracking upon exposure to a freezing environment. The roof tile of the present invention has a limited water absorption of only about 5% water by weight, so that freeze-thaw cycling of the environment will not produce any cracking of the tile.
Moreover, conventional cement and clay roofing materials are often brittle and break when walked upon. The roof tile of the present invention is provided with reinforcing ribs and additional reinforcement throughout by the embedding of reinforcing wire in the ribs and perimeter of the tile, so that normal walking on the tile will not damage it.